Summary

Study aim: The aim of this study was to evaluate the relationship between basic somatic features (body mass and height) and body mass loss in physically inactive young women and men exposed to thermal stress in a dry sauna.

Materials and methods: The research was conducted in 2015 on 685 first-year full-time students (333 women, 352 men), aged 19–20 years old. Nude body mass was measured after the students dried off before and after using the sauna.

Results: An analysis of regression equations indicated that an increase in the body mass of women and men leads to a significant increase in sauna-induced body mass loss. On the other hand, body mass loss decreased with an increase in height in women and men, but to a smaller extent. From among the tested somatic features, body height and body mass, body mass had a decisive influence on body mass loss. Body height had a minimal and statistically non-significant impact on body mass loss.

Conclusions: The results of this study indicate that heavier individuals have an increased risk of dehydration and hyperthermia. Therefore, they should pay close attention to replenishing fluids lost in the sauna. The determination of body mass loss values after a visit to a dry sauna has practical significance because it supports the estimation of the fluid volume required for the maintenance of correct water balance.